Enhanced Resistance to Viruses in 'Columbia' Is Dependent on Salicylic Acid, Correlates with High Glutathione Levels, and Extends to Plant-Pathogenic Bacteria and Abiotic Stress.

Our earlier research showed that an interspecific tobacco hybrid ( 'Columbia' [NEC]) displays elevated levels of salicylic acid (SA) and enhanced resistance to localized necrotic symptoms (hypersensitive response [HR]) caused by tobacco mosaic virus (TMV) and tobacco necrosis virus (TNV), as compared with another interspecific hybrid ( [NE]) derived from the same parents. In the present study, we investigated whether symptomatic resistance in NEC is indeed associated with the inhibition of TMV and TNV and whether SA plays a role in this process. We demonstrated that enhanced viral resistance in NEC is manifested as both milder local necrotic (HR) symptoms and reduced levels of TMV and TNV.

Heat Treatments at Varying Ambient Temperatures and Durations Differentially Affect Plant Defense to in a Resistant and a Susceptible Line.

Our previous research showed that a powdery mildew resistant barley line (MvHV07-17) maintains its resistance to (Bh) even if plants are exposed to a long-term high temperature of 35°C for 120 h before Bh inoculation, whereas such high temperature pretreatment further increases susceptibility to infection in the susceptible barley line MvHV118-17. In the present study, we extended this approach using short-term high-temperature water treatment (49°C for 30 s) to determine how it affects powdery mildew resistance in these barley lines. We found that this short-term heat shock (HS) impaired plant defense responses, as reflected by development of Bh colonies and visible necrotic spots on leaves of MvHV07-17, which does not develop visible symptoms upon Bh inoculation under optimal growth conditions.

Antibacterial effect of essential oils and their components against pv. revealed by microdilution and direct bioautographic assays.

Bacterial spot of stone fruits caused by pv. () is one of the most significant diseases of several species. Disease outbreaks can result in severe economic losses while the control options are limited.

Heat shock-induced enhanced susceptibility of barley to Bipolaris sorokiniana is associated with elevated ROS production and plant defence-related gene expression.

Heat stress alters plant defence responses to pathogens. Short-term heat shock promotes infections by biotrophic pathogens. However, little is known about how heat shock affects infection by hemibiotrophic pathogens like Bipolaris sorokiniana (teleomorph: Cochliobolus sativus).

Antimicrobial Diterpenes from Rough Goldenrod ( Mill.).

is one of the goldenrod species native to North America but has sporadically naturalized as an alien plant in Europe. The investigation of the root and leaf ethanol extracts of the plant using a bioassay-guided process with an anti- assay resulted in the isolation of two antimicrobial components. Structure elucidation was performed based on high-resolution tandem mass spectrometric and one- and two-dimensional NMR spectroscopic analyses that revealed (-)-hardwickiic acid (Compound ) and (-)-abietic acid (Compound ).